湿法炼锌中铟的回收工艺

闪锌矿中的铟主要以硫化铟的形态存在。湿法炼锌过程中大部分铟富集到氧化锌中，氧化锌中铟的回收主要有酸性浸出上清液锌粉置换渣提铟工艺和上清液直接萃取工艺。他们的主流程中都包括了萃取、反萃、反萃液锌片置换、海绵铟熔铸、电解工序，最大不同在于后一种工艺减去了上清液和置换渣浸出工序。生产实践表明，直接萃取工艺铟回收率提高了23％，加工费降低了4．5万形t铟。

Recovery of Indium in Zinc Hydrometallurgy Process

Indium mainly exists in the form of indium sulfide in sphalerite. During the zinc hydrometallurgy process, most of indium is enriched into zinc oxide. Basically, there are two kinds of indium recovery processes from zinc ox- ide, one is indium collection process from replacement slag of acid leaching supernatant and zinc powder, and the oth- er one is direct indium extraction process from supernatant. Both processes include the production procedures：extrac- tion, back-extraction, displacement of back-extraction liquid by zinc, sponge indium casting and electrolysis. The big- gest difference is that the latter process excludes supernatant and displacement slag leaching procedures. The produc- tion practices indicate that the recovery rate of indium by direct extraction process increases by 23% with lowered processing cost by RMB 45,000 per ton indium comparing to indium collection process from replacement slag.